JP2007069630A - Support body and pneumatic run flat tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a run flat tire equipped with a support body having excellent run flat traveling performance wherein a pneumatic tire and a rim are assembled. <P>SOLUTION: The run flat tire 10 is equipped with a curved support part 26 which is disposed in the tire 14, assembled to the rim 12 with the tire 14, is an annular support body 16 capable of supporting a load in run flat traveling, and contains two projections 30A1, A2 projected radially outward in the radial cross section of the support body 16, and an elastically deformable filling body 50 which is filled in a recessed part 30B1 between the projection parts 30A1, A2, and projected radially outward from the projection parts 30A1, A2. The ground pressure rise of the tread part 24 is suppressed, the durability of the tread part 24 is improved, and the durability of run flat traveling is improved, since the filling body 50 and the projection parts 30A1, A2 equally support a tread 24, when the inner pressure of the pneumatic tire 14 drops. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an annular support disposed inside a tire so that it can travel a considerable distance in the state when punctured, and a pneumatic run-flat tire including the support disposed inside About.

Conventionally, it is possible to run flat with a pneumatic tire disclosed in Patent Document 1, that is, even if the pneumatic tire is punctured and the internal pressure of the pneumatic tire becomes 0 kg / cm ² , it is possible to travel with a certain distance with peace of mind. As a new pneumatic tire (hereinafter referred to as “runflat tire”), a core type in which an annular core (support) made of metal or synthetic resin is attached to a rim portion in the air chamber of the pneumatic tire is known. It has been.

In this core type, a rotating core type incorporated in the rim, and a core having two protrusions (two ridges) that support the tread portion of the tire during run flat running in the tire radial cross section attached to the rim. The type is known. The rotating core type has a problem in versatility in that a special wheel for fixing the rotating core is required. On the other hand, the double-core core type is highly versatile because it is attached to a conventional rim.
JP-A-10-297226

By the way, in the conventional two-ridge core type, the back surface of the tread portion of the tire and the two convex portions are in contact with each other to support the load when running the run rat, so the contact portion between the back surface of the tread portion and the convex portion is supported. The load is concentrated and the contact pressure at the contact area is increased. In particular, in a heavy-duty vehicle, since the load applied to the contact portion between the back surface of the tread portion and the convex portion is large, there is a problem that the tread portion is liable to fail, and sufficient running durability cannot be obtained during run flat running. It was.
Also, if the load support part is made flat from the convex part, the contact part between the tread part back surface and the load support part becomes wide when running on a run-flat, so it will be applied to the contact part between the tread part back surface and the load support part. The load is equalized, the contact pressure rise at the contact portion is suppressed, and a failure occurring in the tread portion is suppressed. However, when running on road surfaces with irregularities such as ridges etc., if the load support part is flat, it will be deformed by the impact of the convex part of the road surface and it will be a failure due to the deformed part or running during run flat running There was a problem of increased vibration.

  Here, by assembling to the rim together with the pneumatic tire, the load applied to the contact portion between the back surface of the tread and the support body during run-flat running is equalized, and the rise in the contact pressure of the contact portion is suppressed, and the durability of the tread portion is improved. In addition to ensuring durability, the durability of the support body is ensured even when traveling on uneven road surfaces such as eaves, etc., and the support body excellent in run-flat running resistance and the run-flat running resistance provided with the support body Excellent pneumatic run-flat tires are expected.

  An object of the present invention is to consider the above-mentioned facts, and to provide a support having excellent run-flat running resistance by being assembled to a rim together with a pneumatic tire, and a pneumatic run-flat having excellent run-flat running resistance provided with the support. The purpose is to provide tires.

  A support according to claim 1 of the present invention is an annular support that is disposed inside a pneumatic tire, is assembled to a rim together with the pneumatic tire, and can support a load during run-flat travel, An elastic body integrated with a support portion including two or more convex portions projecting radially outward in a radial section of the support body and a radially inner end portion of the support portion. A leg portion to be mounted; and a resiliently deformable filler that is filled in a concave portion between the convex portions of the support portion and protrudes radially outward from the convex portion in a radial section of the support body. A support characterized by.

  Next, the effect of the support body of Claim 1 is demonstrated. The support can be disposed inside the conventional pneumatic tire (in the air chamber) and assembled to the rim together with the pneumatic tire. When the run-flat tire assembled in this way is mounted on a vehicle and traveled, the support disposed in the tire air chamber when the internal pressure of the pneumatic tire is reduced supports the load instead of the side rubber layer, Run-flat driving is possible.

  By the way, at the time of run flat running, the filling body filled in the concave portion comes into contact with the back surface of the tread portion before the convex portion of the support portion. At this time, the filler undergoes a load and undergoes elastic deformation (compression deformation) inward in the tire radial direction. The filler reduces the load while being elastically deformed, and when the convex portion comes into contact with the back surface of the tread portion, the filler and the convex portion support the load. Since the contact portion between the back surface of the tread portion, the filler, and the convex portion is wide, the load is equalized over a wide range, and an increase in contact pressure is suppressed. As a result, a failure occurring in the tread portion can be suppressed. Therefore, the run flat running durability is excellent.

  In addition, by setting the number of convex portions of the support portion to two or more, the support portion can be deformed to reduce the impact when traveling on a road surface having irregularities such as a bag. As a result, the durability of the support is ensured and the run-flat running durability is improved. Therefore, this support is excellent in run-flat running resistance.

The support according to claim 2 of the present invention is the support according to claim 1, wherein the filler is made of a substance having a density of 2.0 g / cm ³ or less. Support.

Next, the effect of the support body of Claim 2 is demonstrated. By making the filler a material having a density of 2.0 g / cm ³ or less that can withstand compressive deformation, the weight of the run-flat tire is reduced.

  The support according to claim 3 of the present invention is the support according to claim 1 or 2, wherein the filler is made of rubber, urethane, or synthetic resin.

  Next, the effect of the support body of Claim 3 is demonstrated. When filling and attaching the filling body to the concave portion of the support portion, workability is improved by using a material such as rubber, urethane, or synthetic resin that can be integrally molded with the support portion.

The support according to claim 4 of the present invention is the support according to any one of claims 1 to 3, wherein the outermost diameter of the filler is R ₁ , and the outermost diameter of the support is R _2. In this case, R ₂ +1 mm ≦ R ₁ ≦ R ₂ +10 mm is satisfied.

Next, the effect of the support body of Claim 4 is demonstrated. When a load is applied during the run-flat travel, the filler is compressed and deformed radially inward. If R ₁ > R ₂ +10 mm, the protrusion may not be able to contact the back surface of the tread portion even if the filler contacts the back surface of the tread portion and compressively deforms during run flat travel. In this case, the load is concentrated on the contact portion between the filling body and the back surface of the tread portion, so that the ground pressure at the contact portion increases. If R ₂ + 1 mm> R ₁ , the load applied to the back surface of the tread portion by the filler and the convex portion during run-flat running approaches the equalization, but the effect is small. Accordingly, the scope of R ₁ is preferably an _{R 2 + 1mm ≦ R 1 ≦} R 2 + 10mm.

  The support according to a fifth aspect of the present invention is the support according to any one of the first to fourth aspects, wherein the number of convex portions of the support portion is two.

  Next, the effect of the support body of Claim 5 is demonstrated. If there are two convex parts, the support part can be deformed and the impact can be mitigated when traveling on a road surface with irregularities such as ridges, etc. rather than without a convex part and one support body. The durability of the support is ensured, the run flat running durability is excellent, and it is easy to manufacture.

  The support according to a sixth aspect of the present invention is the support according to any one of the first to fifth aspects, wherein 3 mm ≦ H ≦ 25 mm is satisfied, where H is the depth in the radial direction of the recess. It is characterized by that.

  Next, the effect of the support body of Claim 6 is demonstrated. If 3 mm> H, the support can be easily manufactured. However, when the vehicle travels on a road surface with unevenness, such as a ridge, the support portion is deformed and the impact cannot be reduced. If H> 25 mm, the support portion can be deformed and the impact can be reduced even when traveling on a road surface with irregularities such as ridges, but manufacturing becomes difficult. Accordingly, the range of H is preferably 3 mm ≦ H ≦ 25 mm.

  A pneumatic run-flat tire according to claim 7 of the present invention is a carcass formed in a toroid shape between a pair of bead cores, a side rubber layer that is disposed on the outer side in the tire axial direction of the carcass and constitutes a tire side portion, A pneumatic tire provided with a tread rubber layer disposed on the outer side in the tire radial direction of the carcass and constituting a tread portion; a rim for assembling the tire; and an inner side of the pneumatic tire, the pneumatic tire A support body according to any one of claims 1 to 6, which is assembled to the rim together with a tire.

  Next, the function and effect of the pneumatic run flat tire according to claim 7 will be described. When the internal pressure of the pneumatic tire is reduced, the support disposed in the tire air chamber supports the tread portion instead of the side rubber layer, thereby enabling run-flat running.

  By the way, at the time of run flat running, the filling body filled in the concave portion comes into contact with the back surface of the tread portion before the convex portion of the support portion. At this time, the filler undergoes a load and undergoes elastic deformation (compression deformation) inward in the tire radial direction. The filler reduces the load while being elastically deformed, and when the convex portion comes into contact with the back surface of the tread portion, the filler and the convex portion support the load. Since the contact portion between the back surface of the tread portion, the filler, and the convex portion is wide, the load is equalized over a wide range, and an increase in contact pressure is suppressed. As a result, a failure occurring in the tread portion can be suppressed. Therefore, the run flat running durability is excellent.

The support of the present invention is excellent in run-flat running resistance when assembled to a rim together with a pneumatic tire.
The pneumatic run flat tire of the present invention is excellent in run flat running resistance.

  [First Embodiment] (Configuration) A pneumatic run-flat tire using a support according to an embodiment of the present invention will be described with reference to FIG. Here, the run-flat tire 10 refers to a tire in which a pneumatic tire 14 and a support 16 are assembled to a rim 12 as shown in FIG. The rim 12 is a standard rim corresponding to the size of the pneumatic tire 14.

The standard rim is a rim specified by the Yearbook 2004 version of JATMA (Japan Automobile Tire Association), and the standard air pressure is the air pressure corresponding to the maximum load capacity of the Yearbook 2004 version of JATMA (Japan Automobile Tire Association). The standard load is a load corresponding to the maximum load capacity when a single wheel of the year book 2004 version of JATMA (Japan Automobile Tire Association) is applied.
Outside Japan, the load is the maximum load (maximum load capacity) of a single wheel at the applicable size described in the following standard, and the internal pressure is the maximum load (maximum load) of a single wheel described in the following standard. The rim is a standard rim (or “Approved Rim” or “Recommended Rim”) at an applicable size described in the following standards.

  The standards are determined by industry standards that are valid in the region where the tire is produced or used. For example, in the United States, it is “The Tire and Rim Association Inc. Year Book”, and in Europe it is “The European Tire and Rim Technical Organization Standards Manual”.

  As shown in FIG. 1, the pneumatic tire 14 includes a pair of bead portions 18, a toroidal carcass 20 that extends over both bead portions 18, and a plurality of (this embodiment) located in the crown portion of the carcass 20. 2 belt layers 22, and a tread portion 24 formed on the belt layer 22.

  The support body 16 disposed inside the pneumatic tire 14 has a cross-sectional shape shown in FIG. 1 formed in a ring shape, and is vulcanized and formed at both ends of the support portion 26 and the support portion 26. And rubber legs 28. The leg portion 28 is assembled to the rim 12 inside the pneumatic tire 14 when the support 16 is assembled to the rim.

  On the other hand, the support portion 26 has a cross-sectional shape shown in FIG. 2 by molding, for example, a single metal plate such as SUS, high-tensile steel, or aluminum, and is a convex portion that protrudes outward in the tire radial direction. 30A1 and 30A2 and concave portions 30B1 that are convex inward in the tire radial direction formed therebetween, and side portions 30D and 30E that support a load are formed outside the convex portions 30A1 and 30A2 in the tire width direction. Flange portions 30F and 30G extending in the tire width direction are formed at ends (rim side ends) on the inner side in the tire radial direction of the side portions 30D and 30E.

  The depth H of the recess 30B1 preferably satisfies 3 mm ≦ H ≦ 25 mm. Here, the depth H of the recess 30B1 is the depth in the tire radial direction from the outermost vertex in the tire radial direction to the outermost vertex in the tire radial direction of the recess 30B1 on the outer surface in the tire radial direction of the support portion 26. It is H.

Moreover, the filling body 50 is filled in the recess 30B1. The filler 50 is preferably made of a material that can be elastically deformed and has a density of 2.0 g / cm ³ or less, and examples thereof include rubber, urethane, and synthetic resin. In this embodiment, rubber is used for the filler 50. Examples of the rubber include natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), butyl rubber (IIR), urethane rubber (U), and the like. They may be used alone or in combination. These rubber materials contain a filler, and the hardness of the rubber is adjusted by the amount of the filler. Examples of the filler that can be blended with these rubber materials include carbon black, CaCO ₃ , cucumber powder, and silica. In addition, the filler 50 and the leg part 28 use the same kind of rubber material.

Further, the outermost diameter of the packing 50 R _1, when the outermost diameter of the support portion and the R _2, the value of R ₁ is preferably satisfying _{R 2 + 1mm ≦ R 1 ≦} R 2 + 10mm, further, More preferably, R ₂ +3 mm ≦ R ₁ ≦ R ₂ +7 mm is satisfied.

  (Operation) Next, the operation of the pneumatic run-flat tire using the support according to this embodiment will be described. In the run-flat tire 10, when the internal pressure of the pneumatic tire 14 decreases, the support 16 supports the tread portion 24 of the pneumatic tire 14 so that the tire can run. At this time, the filling body 50 filled in the concave portion 30B1 comes into contact with the back surface of the tread portion 24 before the convex portions 30A1 and 30A2 of the support portion 26. At this time, the filler 50 receives a load and elastically deforms (compresses) inward in the tire radial direction. The filler 50 reduces the load while elastically deforming, and when the convex portions 30A1 and 30A2 come into contact with the back surface of the tread portion 24, the filler 50 and the convex portions 30A1 and 30A2 support the load. At this time, the back surface of the tread portion 24 and the contact portion between the filler 50 and the convex portions 30A1 and 30A2 are in a wide range, so that the load is equalized over a wide range and an increase in contact pressure is suppressed. As a result, a failure occurring in the tread portion 24 can be suppressed. Therefore, the run flat running durability is excellent.

  Further, by setting the number of convex portions of the support portion 26 to two or more, the support portion 26 can be deformed to reduce the impact when traveling on a road surface having irregularities such as wrinkles. As a result, the durability of the support 16 is ensured and the run-flat running durability is improved. Therefore, this support 16 is excellent in run-flat running resistance.

  Further, the impact from the road surface is transmitted to the vehicle body via the tread portion 24, the support 16 and the rim 12, and a rubber leg portion 28 is provided on the portion of the support 16 that contacts the rim 12. Therefore, the impact from the road surface is buffered, and the ride comfort during the run-flat running is improved.

  Moreover, since the support part 26 of the support body 16 of this embodiment is filled with the filler 50 in the recessed part 30B1, it has sufficient elasticity in the tire width direction. Further, the leg portion 28 of the support 16 disposed inside the bead portion 18 always presses the bead portion 18 toward the rim flange 12A side (the tire width direction outer side) by the elasticity of the convex portions 30A1, 30A2 and the concave portion 30B1. Yes. Therefore, it is possible to avoid the rim removal of the bead portion 18 even during run-flat traveling.

Moreover, the weight of the run-flat tire 10 is reduced by making the filler 50 into rubber having a density of 2.0 g / cm ³ or less that can withstand compression deformation.

  Further, since the filling body 50 is made of the above material, the filling body 50 is filled after the adhesive is applied to the recess 30B1 of the support body 16, and then the support body 16 and the filling body 50 are attached by vulcanization adhesion. Workability is improved because it can be integrally molded.

Further, since the filler 50 is made of the above-described material, when a load is applied during run-flat travel, it is compressed and deformed inward in the tire radial direction. Here, if R ₁ > R ₂ +10 mm, the protrusions 30A1 and 30A2 are in contact with the back surface of the tread portion 24 even when the filling body 50 is in contact with the back surface of the tread portion 24 and compressively deformed during run flat running. There is a possibility that it cannot be done. In this case, since the load is concentrated on the contact portion between the filling body 50 and the back surface of the tread portion 24, the contact pressure at the contact portion increases. If R ₂ + 1 mm> R ₁ , the load applied to the back surface of the tread portion 24 by the filler 50 and the convex portions 30A1 and 30A2 during run-flat running approaches the equalization, but the effect is small. Accordingly, the scope of R ₁ is preferably to _{R 2 + 1mm ≦ R 1 ≦} R 2 + 10mm, further more preferably not more than _{R 2 + 3mm ≦ R 1 ≦} R 2 + a 7 mm.

  In addition, if there are two convex portions, the support portion 26 is deformed to mitigate the impact when traveling on a road surface having no convex portions and having irregularities such as wrinkles as compared with one support body 16. Therefore, the durability of the support 16 is ensured, the run flat running durability is excellent, and the manufacture is easy.

  If 3 mm> H, the support 16 can be easily manufactured. However, when the vehicle travels on a road surface with irregularities such as a bag, the support 26 cannot be deformed to reduce the impact. If H> 25 mm, the support portion 26 can be deformed to reduce the impact even when traveling on a road surface with unevenness such as a ridge, but manufacturing becomes difficult. Accordingly, the range of H is preferably 3 mm ≦ H ≦ 25 mm.

  [Other Embodiments] In the first embodiment, the support portion 26 of the support body 16 has a two-crested configuration composed of the convex portions 30A1 and 30A2 in the tire radial cross section. The number of the parts may be any number as long as it is 2 or more. For example, as shown in FIG. 2, the convex part has convex parts 30A1 to 30A7, and the concave part becomes concave parts 30B1 to 30B6. Also good.

  Further, in order to reduce the weight of the support portion 26, the support portion 26 may be formed of a thermosetting resin, a thermoplastic resin, or the like reinforced with one or a combination of carbon, aromatic polyamide, and glass fiber. Be good.

  [Test Example] In order to confirm the effect of the present invention, a pneumatic run flat tire according to the first embodiment (hereinafter simply referred to as an example) and a pneumatic run flat tire according to a comparative example (hereinafter simply referred to as a comparative example). A pneumatic run-flat tire according to a conventional example (hereinafter simply referred to as a conventional example) was prepared, and a comparative test was performed.

  The support in the conventional example is a flat plate (support part) formed into a cross-sectional shape as shown in FIG. 4 by a roll forming method, and the support in the comparative example is also shown in FIG. It is formed into a shape. The embodiment is shown in FIG. 1 by roughening the surface (radially outer surface) of the flat plate having the shape of FIG. 4, then performing chemical conversion, applying an adhesive, and then vulcanizing and bonding rubber. A support of such an example was produced.

The flat plate used for the support portion of the support is made of high-strength steel with a thickness of 1.4 mm, the tire size is 275 / 50R19 for all tires, and the rim is a standard rim 8 corresponding to the tire size. 0.0 × 19 was used.
In addition, a large four-wheel drive SUV was used as a test vehicle.

  Next, the pneumatic run flat tires of the examples, comparative examples, and conventional examples are mounted on the test vehicle so that the load is fully loaded, and the left rear wheel is punctured (zero air pressure) and run flat at 90 km / h. The test results are shown in Table 1.

  From the results of Table 1, it is clear that the example is superior in run-flat running resistance than the comparative example and the conventional example. As a result, when running on uneven road surfaces, the support body of the embodiment cushions the impact applied to the convex and concave portions of the road surface to ensure the durability of the support body, and the load applied to the back surface of the tread portion between the filling body and the support portion This is derived from the fact that the durability of the tread portion is ensured by equalizing the pressure over a wide range and suppressing the increase in contact pressure.

It is sectional drawing at the time of rim mounting | wearing of the support body and pneumatic run-flat tire which concern on 1st Embodiment of this invention. It is sectional drawing of the support body which concerns on other embodiment of this invention. It is sectional drawing at the time of rim mounting | wearing of the support body and pneumatic run-flat tire which concern on the comparative example of this invention. It is sectional drawing at the time of rim mounting | wearing of the support body and pneumatic run-flat tire which concern on the prior art example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pneumatic run-flat tire 12 Rim 14 Pneumatic tire 16 Support body 24 Tread part 26 Support part 28 Leg part 50 Filling body

Claims (7)

An annular support body disposed inside a pneumatic tire, assembled to a rim together with the pneumatic tire, and capable of supporting a load during run-flat travel,
A support section including two or more protrusions protruding radially outward in a radial section of the support;
An elastic body integrated with a radially inner end portion of the support portion, and a leg portion attached to the rim when the rim is assembled;
In the radial cross section of the support body, an elastically deformable filling body that is filled in the concave portions between the convex portions of the support portion and protrudes radially outward from the convex portions;
A support characterized by comprising. The support according to claim 1, wherein the filler is made of a substance having a density of 2.0 g / cm ³ or less.   The support according to claim 1, wherein the filler is made of rubber, urethane, or synthetic resin. 4. Any one of claims 1 to 3, wherein R ₁ is an outermost diameter of the filler and R ₂ is an outermost diameter of the support portion, and R ₂ +1 mm ≦ R ₁ ≦ R ₂ +10 mm is satisfied. The support according to claim 1.   The support according to any one of claims 1 to 4, wherein the number of convex portions of the support portion is two.   6. The support according to claim 1, wherein 3 mm ≦ H ≦ 25 mm is satisfied, where H is a depth in the radial direction of the concave portion. A carcass formed in a toroid shape between a pair of bead cores, a side rubber layer that is disposed on the outer side in the tire axial direction of the carcass to form a tire side portion, and a tread portion that is disposed on the outer side in the tire radial direction of the carcass A pneumatic tire provided with a tread rubber layer,
A rim for assembling the pneumatic tire;
The support body according to any one of claims 1 to 6, wherein the support body is disposed inside the pneumatic tire and assembled to the rim together with the pneumatic tire.
A pneumatic run-flat tire comprising:

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